Low-water alarm.



H. NEVILLE.

LOW WATER ALARMx APPLlcATloN FILED JULYH,1913.

Patented Dec. 21, 1915.

2 SHEETS-SHEET 2.

CQLUMBIA PLANDURAPH C0.,WASH1NGTON, D. c.

pin sfrn rar orrrrpn.

HARRY NEVILLE," OF LOS ANGELES, CALIFORNIA, ASSIGNOR 0E" @NE-FIFTH TO PATRICK SHEEDY, ONE-FIFTH TU GEORGE H. GOODNJONE-FIFTH .10 DANEL KELLOGG, AND ONE-FIFTH T0 WILLIAM FMERRY," ALL OF LGS ANGELES, CALI- FORNIA.

Specicationof Letters Patent.

Patented Dec. 21, 19153.

Applicationled July 11,1913. Serial No. 778,498.

To all 107mm it may Concern Be 1t known that l, HARRY Nnvrnnn, a1citi- Zen of the United States, residing. atLos Angeles, in the count-yof Los Angeles` and State of California, have invented certain new and useful improvements in Low-VVa-ter i shown and describedin Letters Patent-of 1,004,896 and4 the United States, Nos. 1,015,703 issued to me, whereby such apparatus is rendered moreeflicient and reliable, and the invention consists in ltheconstruction and adaptationof theparts, as willA be more fully hereinafter pointed out.

lnthe drawings, Figurel is a central vertical section of a. device embodyingv thein vention; Fig'. 2 is a vertical section of a portion of the same on: a plane at right angles to the section plane-of Fig. 1; Fig. is a front view of a locomotive boilerI equipped with the device; Fig. 4 is a side view of such a boiler similarly equipped, andfFig. 5 is a detail of the boiler connection.

Referring` to the drawings, 1 is the steam boiler of a locomotive on which, at a convenient place as hereinafter described, is arranged a cylinder 3 bymeans indicated at 4. At one side of the cylinder is a wing 5 in which is a passage 6 connected atv the top and bottom to cross passages 7 and 8, the latter leading to a fitting y10 whereby a connection. is made with the water space of the boiler.

11 is an air space within the wing' 5. Suspended in the cylinder 3 by a threadedjoint is a cup 16 adapted to contain a mass of mercury 160. rllhere is an annular space-9 surrounding the cup 16, which spaceis connected at the bottom by a space 90 connected in turn to the passage 8 bya vertical passage.

91 the lower end of which is closed by a screw plug.12.. 'lhe upper end 15 of the cup 16 is enlarged and expanded into anannular flans'e 17. The cup 16 is internally threaded and expanded-to form a shoulder 19 above which it is internally threaded 'at `20 toreceive a casingf21.l

.depending stem 33.

ln the upper end` of the casing 21 there is secured a second casing; 260 provided with a valveseat 22, and within this casing there is arranged a reciprocating` valve 23 having a Above the valve there is provided a passageway24 leading to the steam space of the boiler by a suitable pipe indicated at`261. lVithin the casing' 21 is alsoa cylinder 200 in which there is slidably fitted a `fioatingpiston 201 provided at its lower end with a threaded extension 202 by which its effective length may be varied.

The .casing 21 is provided with an annular flange250 having a steam passage 25. To thisiia-nge .there is connected a conduit 280 leading'. :to a control valve to the discharge end of which there `is connected a steam conducting` pipe 29 leading to an alarm whistle arranged at any suitable point, and which pipe 29 is provided with a branch 301 which leads to andis connected with a suitable valve mechanism 32 for controlling` the fuel supply valve of the burner if liquid fuel is used, orto a water spray 320 for spraying the fire with water from the boiler in case solid fuel is used. The whistle and re control mechanisms .formno part ofthe present invention and. are therefore not illustrated in the drawings.

The bodyof the control valve is provided between its inlet and discharge ends with a partition 281 provided with a seat 282 adapted to be engaged by a valve 28 having a stem 284 leading` through a cap 285 adapted to close the upper portion of the valve body and held in position by a retaining nut 280. The lower inner edge 287 of the cap 285 constitutes a. seat adapted to cooperate with the upper part of the valve 28. rlhe valve stem 284 terminates in an upper head 288 between which and the nut 286 there is placed a spring' 289 which holds the stem 284 with its connecting; parts normally in an open position. Passin through the cap 285 is a small leak passage 290.

Arranged within the upper part of the cup 15 and the lower part of the casing 21 is a tube 41 provided with an annular flange 42 which, when the tube 41 is screwed down into the cup16, engages the shoulder 19. Slidably mounted in this tube is a plunger 43, the upper end of which moves through a stuffing box 44. When the plunger 43 is raised ,sufficiently by the expansion of the mercury, as is hereinafter explained, its upper end will engage the threaded extension 202 of the floating piston 200 which in turn being raised, will contact with the valve stem 33, whereby the valve 23 will be lifted from its seat and steam will be permitted to pass through the valve from the pipe 261 to the pipe 280 and valve 28 to the pipe 29 to sound the alarm and actuate the lire-extinguishing mechanism.

The upper end of the plunger 43 is provided with a slot y45 through which there is adapted to pass a lever 451 pivoted at 452. The lever 451 provides means for manually moving the plunger and returning it to its per edgeof the cup whereby the mercury can expand somewhat without moving the plunger. Tt will be readily understood that the plunger itself has to move somewhat before it reaches the threaded extension 202 on the floating piston 200, and the latter has to be actuated before it will contact with the valve stem'33 to move the valve 23.

In the upper end of the cup 16 there is formed a drain passage 52 which communicates with a space between the upper end of the cup and the casing 21, thus permitting any water which might accumulate in this space to be drawn 01T. The floating piston .201 is provided with annular grooves indicated at 203, and it will be noted that the lower end of the stem 33 is not in direct contact with this piston but that there is a slight clearance between them. Also, the piston is provided with a neck 204 in which the extension or timing screw 202 is inserted. This neck fits into an annular aperture in the casing 21 below the cylinder 200, and around this aperture is an annular flange 205 the upper edge of which is slightly above an annular passageway 206 formed in the casing and which communicates with adrain pipe .207. This annular flange forms a barrier to prevent water from the condensed steam which leaks downwardly between the piston 201 and cylinder 200 from getting down into the lower part of the casing 21.

Tt will be noted that the valve 23 is normally kept upon its seat by means of the pressure of the steam within and through the pipe 261 and the passageway 24, and that it is only lifted therefrom to permit the passage .of the steam through the valve inte the small control valve 28 when the eX- normal position after it has been raised by pansion of the mercury has been sufliciently great to move the plunger against the floatmg piston and this 1n turn against the valve stem.

In Figs 5 and 6 there is illustrated a .f'

method of securing the device to the boiler in such a manner as to insure its most etlicient operation. There is suitably secured to the side of the boiler at a convenient location an annular flange 60 having an aperture provided with a spherical or other suitable curved surface 61 and provided with an outwardly extending internally threaded annular flange 62. A hollow nut 63 externally threaded and provided internally with a curved surface 64 corresponding in curvature to the surface 61 is adapted to be brought into threaded engagement with the threads of the annular flange 60. The annular flange and nut are adapted to inclose within their rounded surfaces a spherical member 65 into which there is adapted to be threaded a pipe 66 leading into the steam space of the boiler and a fitting 67 leading into the lower portion of the cylinder 3.

The pipe 66 is so arranged that its inner end is pivotally secured to a bracket 68 and its innermost end terminates at what is known as the neutral low water point of the boiler, z'. e., that point where the level. remains constant for all variations longitudinal or lateral of the position of the boiler itself. This arrangement is for the purpose of preventing the unnecessary actuation of the device and the sounding of the alarm or the extinction of the fire until a real low water level is reached and to avoid the operation of the device, due to rocking or other vibrations of the locomotive.

The operation of the device is as follows: The cup 16 is filled with mercury and the device is connected up to tl e boiler, a, conduit leading from the passage 8 in the cylinder 3 to the neutral low water point of the boiler` as above described. As long as the connection to the boiler is under water the water from the boiler will pass through the passage 8 into the cylinder 3 filling the latter and also the passages 6 and 7. The water thus let into the cylinder will be cooled by the exposed position of the latter to the atmosphere and its heat will be insufficient to cause the mercury in the cup 16 to expand. lVhen, however, the water in the boiler sinks be low the level of the water in the passage 8 it is, of course, below the level of the neutral low water point or very near it, the cylinder 3 will be drained of water and steam from the boiler will enter it and surrounding the cup 16 will heat the mass of mercury therein and cause it to expand and, as it is confined in every other direction, it will rise into engagement with the plunger above it thereby forcing the plunger upward and, after a time depending upon the position of Cil Licence the extension of the floating piston, 1will Icontact with such extension and move the floating piston upward and this in turn will act upon the valve stem and lift the valve 23 olf of its seat and it will admit steam from the boiler' through the valve opening and into the control valve 28, and as this valve is normally opened the steam Will pass through the outlet to the Whistle which Willsound the Warning, and if the branch is provided with the valves the steam will pass to the combustion-controlling device to shut olf the fuel supply when liquid fuel is used, or to spray the lire with Water from the boiler when coal is used. After the Whistle alarm has been sounded the operator, of course, puts the Water-filling apparatus of the boilerl into action to lill the boiler *ith Water up to its normal level. `When this is done and the Water again fills the cylinder 3 surrounding the mercury it will tend to cool the mercury. rlhis, of course, will take some time before the mercury is cooled sutli ciently to allow the plunger to drop, and, in the meantime, the steam from the boiler' Will be passing through both the valve 23 and the valve 28, and the Whistle Will continue to sound, but as soon as the contraction of the mercury has reached such a point that there is an appreciable distance between the upper end of the plungerl and the lower end of the extension of the floating piston, the pressure of the steam upon the latter Will cause it to descend and will automatically close the valve above its seat, thus shutting off the steam, after Which, of course, the valve will be held upon its seat by the steam pressure. ln the meantime, if it is desirable to shut off the Whistle before this series of operations has automatically taken place, the plunger a3 and valve 23 can be returned to their normal positions by pulling down the lever 451, and the operator can also press doivn the stem of the control valve Q8 by pressing down upon the cap 288. rlhis will stop the further passage of the steam to the Whistle and to the lire-extinguishing device, the valve 28 being held to its seat by the steam acting on its upperside. At the same time a slight flow of steam will tal'ze place and leal; through. the small passage 290 indicating to the operator that the valve QS has been closed and that the apparatus is not in an operating condition. As soon as the valve 2o is returned to its seat, either automatically or through. the actua tion of the handle 451, the valve 28 Will open automatically under the influence of its spring and then the apparatus Will. again be in an operative condition, but the Water level cannot drop below the predetermined point.

rl`lie advantage of this construction, that is, b v the use of a. floating piston as compared with the coperation of a plunger directly.T upon the valve stem, and the valve stem acting against the action of a spring, is that in the construction described the steam itself by its elasticity the purpose of the spring formerly employed and holds the steam valve normally on its seat and, at the same time, it assists in the automatic return of the floating piston to its normal position and to the closing of the valve. That is, the devfce has fewer parts to accomplish the desired purpose than pre rions constructions. The advantage of the ball joint between the alarm device and the conduit leading to the neutral low Water point is that the same construction of appa* ratus may be used with boilers having shells of diii'erent curvatures and permits of a rea dv adjustment of the parts, not otherwise possible. The cylinder 9.00 is both removable and changeable and consequently cylinders of difll'erent internal diameters and different lengt-lis may be employed to suit different conditi ons.

l,Vhat l claim is:

l. ',lhe combination With a controlling valve, of a thermostatic actuating device, a piston interposed between the thermostatic device and engaging the valve for transmitting movement from the thermostatic device to the va ve to open said valve, and a passageway controlled by the valve for `conveying steam to the piston to return the same after its movement by the thermostatic device.

2. ln a device of the character described, a casing adapted to contain a steam valve, a stem for the valve, means for moving the valve stem including a cylindrical bearing and floating piston adapted to reciprocate Within the bearing and provided with a depending neck, a drainage passage Within the casing and a barrier separating it from the piston neck.

ln a device of the character described, a casing adapted to contain a steam valve, a stem for the valve, means for moving the valve stein including a cylindrical bearing and a floating piston adapted to reciprocate within the bearing and provided with a depending necln a drainage passage Within the casing and a barrier separating it from the piston neck and comprising an annular fange interposed between the passage and the barrier.

ln an apparatus of the character described, a thermostatic element, a plurality of devices adapted to be successively moved one into engagement With the other after intervals of time by its expansion, a steam valve normally closed by the pressure of the steam, means for moving the valve bv the last of the said series of devices, and mechanism operated by the steam pressure and controlled by such valve.

5. ln an apparatus of the kind described,

a valve Controlling zi steam conduit leading adapted to be successively moved after suitq able time intervals, the first of the series moved from such expansion and the last of the series moved against the vulve, and l-z means for controlling the length of such time intervals.

In testimony whereof I aliix my signature in presence of two witnesses.

HARRY NEVLLE. Witnesses CLARENCE G. CAMPBELL, MARY H. LEWIS.

Copies 0f this patent may be obtained for ve cents each, by addressing the Commissioner of Patents. Washington, D. C. 

